The invention relates to a method of operating a sheet-fed rotary printing machine and to a sheet-fed rotary printing machine having a framework by which at least one cylinder is mounted in a rotatable manner. It is possible for the cylinder to be coupled to a drive or fixed relative to the framework.
Such a method and such a sheet-fed rotary printing machine are disclosed in European Patent Application EP 0 878 301, corresponding to U.S. Pat. No. 6,308,620 B1 to Wadlinger et al. The cylinder is, for example, a varnishing cylinder of a varnishing unit. During operation of the sheet-fed rotary printing machine, the cylinder interacts with an impression cylinder to print a printing-material sheet that is guided through between the cylinder and impression cylinder.
During printing operation of multi-color sheet-fed printing machines, which may have a varnishing unit disposed downstream of them, the transported sheets are only printed with ink in the first printing units. Subsequent printing units or varnishing units idle along therewith. The corresponding impression cylinders are spaced apart from the associated varnishing cylinder. The configuration produces, between the cylinder and impression cylinder, a small gap through which the previously printed sheets are transported. The high machine speed causes the sheets to lift off from an impression cylinder and strike against the associated cylinder.
In order to make possible smear-free sheet travel with printing, varnishing or finishing units switched off, Wadlinger proposes the formation, on or in the cylinder, of a sheet-directing configuration by which a sheet that is transported past the associated cylinder by the respective impression cylinder is kept away from the cylinder. The sheet-directing configuration is accommodated, for example, in a channel that runs axially in the lateral surface of the cylinder. A blowing tube that is connected to a blowing-air connection on the cylinder end side forms, for example, the sheet-directing configuration. The blowing air passing out of the blowing tube serves for forcing away from the cylinder, in the direction of the associated impression cylinder, a sheet that is transported through between the cylinder and the impression cylinder.
To ensure satisfactory functioning of the sheet-directing configuration, it is necessary for the cylinder to be uncoupled from the associated drive and fixed in a specific angular position relative to the framework. According to Wadlinger, the cylinder is uncoupled from the drive by a coupling and fixed relative to the machine framework by a catch.
It is accordingly an object of the invention to provide a method of operating a sheet-fed rotary printing machine having a framework by which at least one cylinder is rotatably mounted and sheet-fed rotary printing machine for implementing the method that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and that make it possible for the cylinder to be straightforwardly uncoupled from the drive and/or fixed relative to the framework. Another objective is for the method to be cost-effective to implement and for the sheet-fed rotary printing machine according to the invention to be cost-effective to produce.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a method of operating a sheet-fed rotary printing machine, including the steps of mounting at least one rotating cylinder to be selectively coupled to a drive and fixed relative to a framework and moving an actuator to both uncouple the cylinder from the drive and fix the cylinder relative to the framework.
Simply by movement of an actuating element or actuating member, the cylinder is both uncoupled from the drive and fixed relative to the framework and vice-versa. The method and configuration give the advantage that, following the uncoupling operation, the cylinder is automatically and reliably fixed relative to the framework. Instead of a coupling and a catch, all that is required is for a single actuating element to be moved.
In accordance with another mode of the invention, the cylinder is made to rotate in the circumferential direction by the movement of the actuating element, in particular, displacement of the actuating element parallel to the longitudinal axis of the cylinder. The specific rotation of the cylinder through a few degrees serves for adjusting the circumferential register. It is particularly practical if the movement of a single actuating element is used for coupling and fixing purposes and for adjusting the circumferential register. Preferably, the actuator is an actuating element or an actuating member.
With the objects of the invention in view, there is also provided a sheet-fed rotary printing machine, including a framework, a drive, at least one cylinder rotatably mounted to the framework, the cylinder to be coupled to the drive or fixed relative to the framework, and a fixing and coupling configuration connected to the cylinder to both uncouple the cylinder from the drive and fix the cylinder relative to the framework. The fixing and coupling configuration both uncoupled the cylinder from the drive and fixes it relative to the framework and vice-versa. Prior to uncoupling from the drive, the cylinder is stopped in a defined angle position by the drive itself. The combined fixing and coupling configuration allows reliable uncoupling and fixing of the cylinder in a straightforward manner.
In accordance with a further feature of the invention, the fixing and coupling configuration includes an actuating element that can be displaced parallel to the longitudinal axis of the cylinder. The axial displacement of the actuating element serves for uncoupling and fixing the cylinder and for adjusting the circumferential register.
In accordance with an added feature of the invention, there is provided an actuating gearwheel that is fixed axially, and mounted rotatably, on the actuating element, coaxially with the cylinder, and engages with a driving gearwheel. Through the actuating gearwheel, the driving torque of the driving gearwheel is transmitted to the cylinder either directly or through the actuating element. The rotatable mounting ensures that the actuating gearwheel runs along with the driving gearwheel when the cylinder is fixed relative to the framework and that the driving gearwheel rotates.
In accordance with an additional feature of the invention, the actuating element or an actuating member that can be moved relative thereto can be displaced axially between a coupling position, in which the cylinder is coupled to the drive, and a fixing position, in which the cylinder is fixed relative to the framework. The axial displacement of the actuating element or of the actuating member takes place directly or indirectly by an actuating motor.
In accordance with yet another feature of the invention, in the coupling position of the actuating element or of the actuating member, the actuating gearwheel is connected to the cylinder in a form-fitting manner, through a first form-fitting element, directly or indirectly through the actuating element. The form-fitting connection between the actuating gearwheel and the cylinder ensures that the cylinder is driven during printing operation. The form fit prevents the actuating gearwheel and the cylinder from rotating relative to one another, which could have an adverse effect on the circumferential register during operation.
A further preferred exemplary embodiment of the sheet-fed rotary printing machine is characterized in that the first form-fitting element includes a bolt that is fitted on the actuating gearwheel and, in the coupling position of the actuating element, is at least partially accommodated in a bore that is provided at the end of a flange or of an arm that is provided on the cylinder. The bolt may be formed integrally with the actuating gearwheel. As a result of the above-described axial fixing of the actuating gearwheel on the actuating element, axial displacement of the actuating element is transmitted to the bolt.
In accordance with yet an added feature of the invention, the first form-fitting element includes a bolt that is prestressed by a spring, is fitted on the actuating element or the actuating member, and, in the coupling position of the actuating element or the actuating member, is at least partially accommodated in a bore that is provided in the actuating gearwheel. By virtue of the spring prestressing of the bolt, the cylinder remains coupled to the driving gearwheel even in the event of an auxiliary-power failure.
In accordance with yet an additional feature of the invention, in the fixing position, the actuating element is connected to the framework through a second form-fitting element. The form-fitting connection between the cylinder and framework ensures that the cylinder is at a precise angle in the fixing position. The configuration makes it possible for a sheet-directing configuration disposed on or in the cylinder to be positioned precisely in relation to an associated impression cylinder.
In accordance with again another feature of the invention, the second form-fitting element includes a bolt that is provided on the actuating element or the actuating member and, in the fixing position of the actuating element or of the actuating member, is at least partially accommodated in a bore that is provided on the framework. To ensure a clear angular relationship between the actuating gearwheel and the cylinder and/or between the cylinder and the framework, only one bolt or protrusion is provided in each case for the form-fitting connection between the actuating gearwheel and the cylinder and/or between the cylinder and the framework. It is also possible, however, for a plurality of bolts or protrusions to be disposed on concentric circles with different radii or for a plurality of bolts or protrusions to be disposed asymmetrically on one circle. Finally, it is also possible to use a plurality of bolts or protrusions that differ from one another in terms of size and shape. The bolts or protrusions and the associated bores or recesses are constructed to complement one another in each case to ensure a form fit between the respective parts.
In accordance with again a further feature of the invention, the second form-fitting element is connected, in particular integrally, to the first form-fitting element and, in the fixing position of the actuating element or of the actuating member, is retained on the framework by a latching configuration. The latching configuration ensures that, despite the spring""s prestressing of the first form-fitting element in the opposite direction, the second form-fitting element remains connected to the framework, to be precise, even in the event of an auxiliary-power failure.
In accordance with again an added feature of the invention, there is provided an actuating member mounted on the actuating element. The actuating member is provided with a first and a second form-fitting element and can be moved between a coupling position, in which the cylinder is connected to the actuating gearwheel in a rotationally fixed manner through the first form-fitting element, and a fixing position, in which the cylinder is connected to the framework in a rotationally fixed manner through the second form-fitting element. The actuating member makes it possible for the cylinder to be uncoupled and fixed. A slight rotation of the cylinder for the purpose of adjusting the circumferential register may take place through a defined adjustment, in particular, a slight axial displacement, of the actuating element.
In accordance with again an additional feature of the invention, the actuating member can be actuated by an actuating configuration and, in the non-actuated state, is retained in the coupling position or fixing position by at least one prestressed spring. As a result, the cylinder remains in its current state even in the event of an auxiliary-power failure.
In accordance with still another feature of the invention, the actuating member is formed by a lever that is fitted pivotably on the actuating element and at one end of which the first and the second form-fitting elements are disposed on opposite sides with respect to one another. The configuration allows a quick switchover between the fixing and coupling positions.
In accordance with still a further feature of the invention, the actuating member is formed by a slide that is guided in a displaceable manner relative to the actuating element. The dimensioning of the slide and of the complementary recesses in the cylinder, the actuating gearwheel, and the framework makes it possible to prevent the cylinder from rotating during the switchover between the fixing and coupling positions. For such a purpose, the slide has to be long enough for the cylinder briefly to be connected in a form-fitting manner both to the actuating gearwheel and to the framework.
In accordance with still an added feature of the invention, the cylinder can be fixed relative to the framework by a further actuating element. The further actuating element serves for fixing the cylinder irrespective of the position of the first actuating element. In the exemplary embodiment, the first actuating element, thus, serves only for coupling the cylinder to the actuating gearwheel and for retaining the circumferential register.
In accordance with still an additional feature of the invention, the further actuating element is formed by a slide that is guided on the framework and, for the purpose of fixing the cylinder, can engage at least partially in a recess that is formed on a flange or an arm of the cylinder. Instead of the slide, it is also possible to use a lever that is provided, at one end, with a form-fitting element that can engage in the recess formed on the cylinder.
In accordance with another feature of the invention, the further actuating element is mounted such that it can he displaced radially and such that it is resilient tangentially to the cylinder. The resilient mounting in the direction transverse to the adjusting direction of the actuating element serves for compensating for positioning inaccuracies during the switchover operation.
In accordance with a further feature of the invention, the fixing and coupling configuration includes a first additional actuating element, which serves for fixing the original actuating element relative to the framework, and a second additional actuating element, which serves for coupling the actuating element to the actuating gearwheel. The two additional actuating elements may be coupled to one another through a control configuration to ensure a disruption-free switchover between a fixing position and a coupling position of the cylinder. In the exemplary embodiment, the original actuating element serves for retaining the circumferential register.
In accordance with an added feature of the invention, the first and the second additional actuating elements each include a form-fitting element, which can be accommodated in corresponding recesses in the original actuating element and the actuating gearwheel. The two form-fitting elements ensure that rotation of the cylinder and framework relative to one another in the fixing position and rotation of the cylinder and actuating gearwheel relative to one another in the coupling position are reliably prevented. To counteract relative rotation during the switchover operation, the two form-fitting elements may simultaneously engage with their complementary recess for a short period of time.
In accordance with an additional feature of the invention, the actuating element is connected to the cylinder in a rotationally fixed manner through a form-fitting element, for example, a feather key or a toothing formation, in particular, a straight toothing formation. The configuration ensures, in particular, in the fixing position, that the cylinder is fixed in a defined angle position. At the same time, the rotatable mounting of the actuating gearwheel on the actuating element ensures that the actuating gearwheel, which engages with the driving gearwheel on a permanent basis, can rotate during operation.
In accordance with yet another feature of the invention, the actuating gearwheel and the driving gearwheel are provided with an oblique toothing formation. Accordingly, axial displacement of the actuating element causes the cylinder, coupled to the actuating element in a rotationally fixed manner, to rotate in order for the circumferential register to be adjusted. The axial displacement of the actuating element and the rotation of the cylinder only take place to a small extent. The coupling between the actuating element and the cylinder may take place, for example, by a feather key or a straight toothing formation. The configuration ensures that the actuating element can be displaced axially relative to the cylinder.
In accordance with yet a further feature of the invention, the actuating element is subjected to the action of a threaded bolt that, driven rotatably by a motor, is accommodated in a threaded bore that is provided in a flange that is connected to the framework in a rotationally fixed manner. Through the threaded bolt, the rotary movement of the motor is converted into a translatory movement of the flange, which is coupled to the actuating element. An axial bearing is preferably in provided between the flange and the actuating element to make it possible for the actuating element and the cylinder to rotate relative to the flange as far as possible without friction.
In accordance with yet an added feature of the invention, the actuating element is prestressed by a spring. The spring prestressing holds the actuating element in abutment against the flange.
In accordance with yet an additional feature of the invention, the threaded bolt has a self-locking thread. The self-locking ensures, in conjunction with the spring""s prestressing, that the threaded bolt remains in its respective position in the event of an auxiliary-power failure. This means that an undesired coupling operation does not take place.
In accordance with again another feature of the invention, there is provided a bevel formed on the bolt. The bevel serves for compensating for positioning inaccuracies during coupling and fixing of the cylinder. The form-fitting counterpart to the bolt is preferably provided with a complementary funnel-shaped widening.
In accordance with a concomitant feature of the invention, the actuating gearwheel is braced in relation to the driving gearwheel by a clamping gearwheel. The configuration ensures play-free force transmission between the driving gearwheel and the cylinder during printing operation.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method of operating a sheet-fed rotary printing machine and sheet-fed rotary printing machine, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.